The project is designed to apply the techniques of molecular biology to the kidney. Initially, the gene for aldose reductase in the kidney is being cloned and sequenced. The starting material is a continuous cell line derived from rabbit renal medulla. The cells produce increased levels of aldose reductase when grown in hypertonic media. A cDNA library prepared from cells grown in hypertonic medium will be prepared in lambda gtll. Expression of aldose reductase will be detected using a high affinity polyclonal antibody.